Internal-combustion engine.



W. CAMPBELL.

INTERNAL COMBUSTION ENGINE.

APPLICATION FILED sEPT,1a,1911

1,091,629. Patented 1111111131, 1914.

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W. CAMPBELL.

INTERNAL coMBUsTloN ENGINE.

APPLICATION FILED SEPT.18,1911. 1,091,629. Patented Mar. 31, 1914.

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Witnesses:

ED SATES PlENT OFFICE.

WILFBEQ CAMPBELL, OF SCHENECTADY, NEW YORK, ASSIGNOR T GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

INTEBNAL-COMBUSTION ENGINE.

Specification of Letters Patent.

Patented Mar. 31, 1914.

Application led September 18, 1911. Serial No. 849,912.

To all 'whom 'it may concern Be it known that I, Wnrrnao CAMPBELL, a subject of the King of'Great Britain, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements/1n Internal-Combustion Engines, of which the following is a specification.

Il`his invention relates to internal combustion engines.

While not limiting the invention to any particular type of engine, it will be described as applied to an engine of the fourl cycle typeV in which it is possible to secure an explosion at each revolution of the shaft, to do away with valve-actuating gearing, to avoid exposing the valves to the pressures developed by the explosion of the charge, to effect a good compression, to secure a complete scavenging, and to obtain a long throw of the crank with a short stroke of the piston. To accomplish these desirable results, I use two pistons in the same cylinder, connected with the crank shaft by an improved system of rods and rock-arms or cranks `having a small number of parts adapted to eilicently transmit the forces to which they are subjected, whereby one piston eifects the suction of the charge at a relatively slow rate, and the scavenging of the cylinder, the other piston serving to compress the charge at a relatively rapid rate and vexecute the power stroke. The valves are held closed by springs, one valve opening in response to the suction stroketo admit the explosive charge, and the other opening during the scavenging stroke to permit the gases tol escape. The compression and tiring of the charge take place in a part of the cylinder remote from the ports through which the vas enters and leaves the cylinder, so that the Valves are not exposed to the high working pressure.

In the accompanying drawings, Figure 1 is a vertical section of an upright engine ernoodying my invention, Fig. 2 is `a section at -rightangles to Fig. 1, and Figs. 3, 4, 5, and 6 are diagrams illustrating the cycle of operation. A

The cylinder 1 is open at each end and its length is almost three times the stroke. The

middle ortion of the cylinder constitutes the wor ing 'chamber for the compression and explosion of the charge, and is provided 255 with a water jacket 2. At the upper end of this chamber is an inlet port 3 preferably controlled by a spring seated inwardlyo ening valve 4. Opposite the port 3 and at t e same level is the exhaust port 5 refer- `ably controlled by a spring seateld outwardly-opening valve 6. At the lower end of the working chamber islocated the spark p lug7 for igniting the charge but the invention 1 s not l1mited to an engine in which the ignition is produced in this particular manner. In each end of the cylinder is a trunk piston. The upper piston 8 is the power piston and has a long transverse pm 9 atits uplper end whose ends carry slide-blocks l0, w 1ch reciprocate in guide-slots 11 cut longitudinally in the upper walls of the cylinder. The ends of the pin project beyond the blocks and form trunnions for two links or connecting rods 12 whose lower ends are ivoted` to rock-arms or cranks 13 on a rocking crank shaft 14 and 15, suitably journaledV in bearings 16 in the walls of the crank case 17 of the engine. On the inner portion of said shaft, inside the crank case, are the rock-arms or cranks 18 which are connected by a wrist pin 19 to which is pivoted the pitman 2O attached to the lower piston 2l by the trunnion pin 22. The wrist pin 19 is connected by one or two connecting rods 23 with a crank 24 on lthe engine shaft 25. The arms 13 and 18 are of longer radius than the crank 24, so that they have a limited arc of oscillation, while the crank is making a complete revolution.

The operation can be understood best from the diagrams Figs. 3 to G. With the crank 24' on the upper dead center at a the pistons are close together, with their adjacent faces on the level of the ports 3 and 5, as shown in Fig. 3. A quarter revolution of the crank 24 in the direction of the arrow brings it to position Fig. 4. The upper ends of the rock-arms 13 have swung over in an arc whose chord is substantially horizontal, the upper piston 8 lifting slightly and then returning about to its former position. The rock-arms 18, however, have swung downward on thc arc z/ y s arms 18 have moved through an arcy y2 which is almost horizontal, so that the lower piston 21 has movedbut slightly from the position it occupied in Fig. 4, dropping just below the spark plug 7. Duringl this change 4in positions, the piston S, therefore, ap-

proaches the piston 21, and compresses the charge between them. Just before the crank .reaches the lower dead center the charge is `ignited by the spark plug. The expansion of the gas drives up the upper piston 8 to the )ositio-n shown in Fig. 6 exertin a ull on the. links 12 and a thrust on the rods 23 and causing the crank to move to position d and exert a driving torque on the shaft 25.`

l v fore, operates on the four-cycle principle,

lbut all four steps of the cycle are performed in one revolution of the crank shaft, which thus receives a driving impulse once in each revolution, instead of once in two revolutie-ns, as is ordinarily the case in four-,cycle engines. Moreover, the compression and explosion of the charge occur at the lower part of the cylinder, entirely removed from the ports 3 and 5, and the valves 4 and 6, which are subjected only to the pressure and temperature of the exhaust. Owing to the relative positions of the arms 13 and 18 and the crank 24 at the instant the charge is ignited, the piston 8 can exert its power most advantageously. (See Fig. 5.)

It will be observed that the pistons operate alternately, the lower one making an instroke and an outstroke while the upper one is stationary, and then remaining stationary while the upper one makes an instroke and an outstroke.

-lt will also be observed that the upper piston cooperates with the inlet and exhaust ports in the same manner as the piston of a two-cycle engine, closing them.` after the charge has been drawn in and keeping them closed during compression and ignition, and then opening them for the discharge of the burnt gases through the exhaust port and the intake of a fresh charge.

While I have illustrated the invention as applied to an upright engine, it is evident that whether the cylinder is vertical or horizontal is immaterial. Furthermore, the cylinder may be air cooled instead of water cooled, if desired.

ln accordance with the provisions of the VVhatI claim as new and desire'to secure' v by Letters Patent of the United States is :e

1. An internal combustion engine having a cylinder and two pistons therein, an engine crank shaft, and a connection between the pistons and the engine shaft, comprising a second cranksshaft, cranks onsaid second crank shaft at suchl an angle to each other that when one is moving about an are, the chord of which is substantially horizontal, the other is moving about an arc, the chord. of which is substantially vertical, means connecting the two pistons to the cranks, and a connection between the two crank-shafts.

2. An internal combustion engine having 'second crank-shaft parallel to the engine shaft provided vwith a. pluralityof cranks, means connecting the two pistons to the cranks of the second shaft, the cranks to which the pistons are respectively connected being arranged at an angle to eachother, and means connecting the two crank-shafts.

3. An internal combustion engine having a cylinder and two pistons therein, a rotating engine crank-shaft arranged at one side of the axis of the cylinder, and connections between the pistons and the engine shaft comprising a rocking crank-shaft arranged on the opposite side of the axis of the cylinder (and parallel to the engine shaft, the axis of one shaft being nearer the cylinder than the other, means connecting the two pistons to the cranks of the rocking shaft, the cranks to which the pistons are respectively connected being arranged at an angle to each other, and means connecting the two crankshafts.

1. An internal combustion engine,.having a cylinder containing inlet and exhaust ports, two pistons in said cylinder, a rock arm one end of which moves about a given axis in an are which at first lies transverse 'to the axis of the cylinder -and isy Subscv ing engine crank-shaft, and a connection between the pistons and the engine shaft comprising a rocking crank-shaft parallel to the engine shaft, outside connectlng rods conf necting one piston to the rocking shaft, an inside connecting rod connecting the other piston to the rocking shaft, the cranks to lwhich the two pistons are connected being arranged at an angle to each other, and a connection from one of said cranks to the engine shaft.

6. An internal combustion engine having a cylinder and two istons therein, a rotating engine crank-siliaft, a rocking crankshaft located at one side of the axis of the cylinder with its axis parallel to the axis of the first shaft and having a plurality of cranks of greater length than the crank radius of the engine shaft, a connection between the two crank-shafts, and connections between the pistons and the cranks of the rocking shaft, the cranks to which the pistons are respectively connected being arranged on opposite sides of the axis of said shaft and at such an angle to each other that when one is moving about an arc, the chord of which is substantially horizontal, the other is moving about an arc, the chord of which is substantially vertical.

7. An internal combustion engine, having an upright cylinder open at both ends, longitudinal slots in the upper port-ion thereof, two pistons in thel cylinder, the upper one having a transverse pivot. pin extending out through said slots, a crank case having aX- ially alined rock-shafts in the sides thereof, outer rock-arms on said shafts, links connecting said arms with said pivot pin, inner rock-arms on said shafts connected by a wrist pin, a pitman connecting said wrist pin with the lower piston, a crank shaft and crank, and a connecting rod between said crank and said Wrist pin.

In witness whereof, I have hereunto set my hand this 16th day of September 1911.

WILFRED CAMPBELL.

Witnesses:

HELEN ORFORD, T. J. SEABOLT. 

